Simplify the expression. $(5z-1)(-5z-5)$
First distribute the ${5z-1}$ onto the ${-5z}$ and ${-5}$ $ = {-5z}({5z-1}) + {-5}({5z-1})$ Then distribute the ${-5z}.$ $ = ({-5z} \times {5z}) + ({-5z} \times {-1}) + {-5}({5z-1})$ $ = -25z^{2} + 5z + {-5}({5z-1})$ Then distribute the ${-5}$ $ = -25z^{2} + 5z + ({-5} \times {5z}) + ({-5} \times {-1})$ $ = -25z^{2} + 5z - 25z + 5$ Finally, combine the $x$ terms. $ = -25z^{2} - 20z + 5$